Systems for the detection of chemical and biological weaponry are of increasing international interest. A biological weapon incorporates an organism (bacteria, virus or other disease-causing organism) or toxin found in nature as a weapon of war. Biological warfare agents of critical concern include bacterial spores such as Bacillus anthracis (anthrax), Clostridium tetani (tetanus), and Clostridium Botulinum (botulism). Particularly Bacillus bacteria and Clostridium bacteria form bacterial spores.
Dipicolinic acid (pyridine 2,6 dicarboxylic acid) (DPA) is a major component of bacterial spores and it is unique in that it has only been found in spores. Up to 15% of a spore's dry weight may consist of DPA complexed with calcium ions (CaDPA).
U.S. Pat. Nos. 5,701,012 and 5,895,922 disclose a process for detecting the existence of biological particles such as spores whereby fluorescence of the particle is measured and compared against predetermined fluorescence levels.
Bronk et al in Chemical and Biological Sensing (P. J. Gardner, Ed. Proc. SPIE vol 4036 (2000) pp 169-180) disclose observing an increase in fluorescence intensity following heating spores in a water suspension to cause release of DPA by the spores into the water and then exposing the water to UV light.